Lithium ion batteries are widely used in the electric industry, information technology industry, and other fields. The lithium ion batteries have numerous advantages, such as high voltages, high capacities, no memory effects, low pollutions, small volumes, high specific energy, small resistances, low self-discharge, high-cycle life, safe, and adjustable shapes.
Lithium ion batteries require that a battery core containing an electrolyte solution is placed in a sealed shell. Typically, the sealing material of the shell is metal-rubber composites. The electrolyte solution may leak from the sealed shell after the battery is recharged for certain times.
One example in the prior art discloses a metal-resin composite. The composite comprises: (1) a magnesium alloy; (2) a layer having a metal oxide, a metal carbonate, or a metal phosphate on the surface of the magnesium alloy; and (3) a resin layer. The main component of the resin layer is a polybutylene terephthalate resin or a polyphenylene sulfide resin, a thermosplastic resin with crystalline property. The resin is introduced into concavities of the surface of the alloy by an injection molding process.
Another example in the prior art discloses a method of manufacturing a composite of an aluminum alloy and a resin. The method comprises the steps of: immersing the aluminum alloy into at least one selected from the group consisting of ammonia solutions, hydrazine solutions and water-soluble amide compounds; and applying a polyphenylene sulfide resin into the alloy by an injection molding method. The method requires complex steps.